An external network modeling approach for online security analysis

An approach that combines the load flow and state estimation techniques is proposed to improve the numerical stability and provide an external network model for online security analysis. An initial load flow study that provides a preliminary solution for the external network is followed by a state estimation using pseudomeasurements and proper weighting factors. Methods for handling multiple observable islands in the external network modeling process are described, and simulation tests are carried out on a practical system with realistic complexity.<
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